The present invention relates to a single-sided adhesive vapour barrier tape which has a vapour barrier strip and adhesive strips.
A single-sided adhesive vapour barrier tape is disclosed, for example, by DE 297 23 454. This adhesive vapour barrier tape has an airtight substrate which is coated on one side with a plastic capable of diffusion and is provided on the other side with a contact adhesive. An adhesive vapour barrier tape of this type can be bonded over the entire width. Because of its construction, this adhesive tape is airtight. Such airtightness is required nowadays in roof construction. For this purpose, it is usual for vapour barriers to be incorporated in an airtight manner. For this purpose, airtight sheets or webs of paper or plastic are tacked beneath insulation, on the warm side, and are bonded so as to overlap and be airtight.
In roof construction, for reasons of the construction sequence, it is often not possible to achieve the absolute airtightness required by statute in an area of a top beamxe2x80x94also called a ridge purlin. For this reason, vapour barrier webs which run up obliquely in the roof on both sides from the masonry, in the direction of the gable, are connected at the sides to the ridge purlin in a complicated manner over the entire ridge length. For this purpose, a carpenter or roofer generally lays a film strip with a width of about 40 to 70 cm over the entire length of the ridge purlin. This is only possible at a time at which the unfinished roof storey has been set up, that is to say before the installation of any insulation and the entire roof construction, such as the roof tiles or facework.
The foil strip laid onto the ridge purlin is either cut out from vapour barrier material or else already supplied in a width of 40 to 70 cm. Placed on the ridge purlin, the foil strip then hangs down on both sides of the ridge purlin. In order to ensure the safety of the people working on the roof storey, the foil strip is generally non-slip on its side pointing upwards and is additionally firmly tacked to the ridge purlin using staples. As a result, the foil strip cannot be moved on the ridge purlin. The ridge purlin covered with the foil strip can therefore be walked on without risk of slipping even during the construction of the roof and the installation of insulation.
After the ridge purlin has been covered with the foil strip, the roof is insulated and the construction of the roof is provided with sarking felt and tiles. On the inside, a vapour barrier is then installed in an airtight manner as far as the ridge purlin, that is to say the gable. In the gable area, the hanging portions of the film strip fixed to the ridge purlin can then be folded up onto the adjacent vapour barrier and joined in an airtight manner using a corresponding single-sided or double-sided adhesive tape. Appropriate adhesive tapes which ensure airtightness are used for this purpose.
It is known for such a film strip, as a vapour barrier strip, with a length of 40 to about 70 cm to be provided with a double-sided adhesive tape in a left-hand and a right-hand portion and delivered in this way to a building site. A manual worker is then able to produce an airtight bond between the ridge-purlin strip resting on the ridge purlin and the flat vapour barrier fastened to the roof truss. This adhesive vapour barrier strip has the double-sided adhesive tapes, which are about 2 cm wide, at a distance from the edge of the film strip.
The object of the present invention is to provide an adhesive vapour barrier strip with a vapour barrier strip which permits reliable, airtight bonding, in particular in the roof gable area, when finishing a roof.
This object is achieved with a single-sided adhesive vapour barrier tape and with a method of producing a vapour-tight joint when finishing a roof at a ridge purlin.
A single-sided adhesive vapour barrier tape with a vapour barrier strip is constructed in such a way that the vapour barrier strip has a width between at least 35 cm and preferably 100 cm, and a single-sided adhesive vapour barrier strip is in each case arranged on both long edges of the vapour barrier strip. Each adhesive vapour barrier strip is provided on its adhesive side with a protective means which can be pulled off separately and prevents inadvertent adhesion of the adhesive strip. The adhesive vapour barrier strip preferably has a width of between 4 cm and 10 cm. On the one hand, this permits secure fastening and tightness between the vapour barrier strip and the adhesive vapour barrier strip itself. On the other hand, the result is that a sufficient width of the adhesive side remains to provide an airtight joint to an adjacent vapour barrier belonging to the ridge purlin. The single-sided adhesive vapour barrier strip is in particular applied in such a way that a part thereof, approximately 30 to 70%, preferably about half of its width, bonds to the vapour barrier strip or is welded to the latter. The portion appearing beyond this is covered on the adhesive side with a protective paper. For the purpose of airtight bonding, the protective paper needs to be pulled off only from the projecting adhesive side, this portion of the adhesive vapour barrier tape needs to be folded up and rubbed onto the vapour barrier. The joint produced in this way is airtight, and because of the adhesive side being present on only one side, the risk that creases or waves will be produced is minimized, which would lead to the joint between the adhesive vapour barrier tape and the flat vapour barrier of the roof not being airtight. An improvement to the achievable airtightness, in particular as viewed in terms of long-term effects, results if a film substrate, which bears the adhesive, is used for the adhesive vapour barrier strip. This film substrate is particularly smooth and, therefore, even in the event that creases occur, is able to close these in an airtight manner on the basis of a rubbing action.
It is preferable for the portion of the adhesive vapour barrier strip which is provided with a protective means and projects with respect to the vapour barrier strip to be 1.5 cm to 3 cm wide. Since, in roof finishing, wood is the constructional material normally used, butxe2x80x94considered over timexe2x80x94continues to xe2x80x9cworkxe2x80x9d, in particular on account of the large temperature differences between summer and winter, such a width of the adhesive vapour barrier strip makes it possible for there to be an adequate adhesive area in order to be able to compensate for distortion of the constructional materials used. Particular strength results if the adhesive vapour barrier strip is co-integrated into a layer construction of the vapour barrier strip. The vapour barrier strip is constructed of several layers, for example, so that the adhesive vapour barrier strip can be arranged between two of these layers. There is also the possibility of the adhesive vapour barrier strip forming one surface of the vapour barrier strip and, at the same time, terminating flush with the adjacent surface of this vapour barrier strip. This is obvious in particular when the adhesive vapour barrier strip is welded to the vapour barrier strip, since as a result the production of seams or incipient seams can be avoided.
A further configuration of the adhesive vapour barrier strip provides for the adhesive vapour barrier strip to be partially bonded onto the vapour barrier strip. The vapour barrier strip is preferably approximately 60 cm wide. This makes it possible, on the one hand, for various constructions of the connection between the ridge purlin and roof beam, to provide an adequate area of vapour barrier strip. On the other hand, such a length of the vapour barrier strip is sufficiently flexible, because of its width, to be able to compensate for extremely small movements of the beams without the airtightness of the vapour barriers being threatened. Such a wide vapour barrier strip preferably has on its long edges adhesive vapour barrier strips with an adhesive side which is to be bonded and is provided with a protective means that can be pulled off and which has a width which is equal to or greater than the width of the projecting adhesive strip.
The adhesive vapour barrier strip described above is used in particular during the production of a vapour-tight joint when finishing a roof at a ridge purlin. The vapour barrier strip is laid over the ridge purlin and, for the purpose of vapour-tight sealing, the respective protective means is then pulled off the adhesive vapour barrier strips, in order to bond the adhesive vapour barrier strips to an adjacent vapour barrier in a vapour-tight manner.